FHR-SCTP: The Research of a Quality Aware SCTP Congestion Control Mechanism to Improve Handover Efficiency

Stream Control Transmission Protocol (SCTP) provides two particular features difference from Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) in transport layer. One is Multi-homing, and the other is Multi-streaming, Furthermore, Multi-homing is a good feature for soft-handover. This paper will discuss the issue that the soft-handover efficiency implemented by Multi-homing, and improving it. When SCTP changes to other primary path at handover, the transmission rate will greatly decline. Because the new primary path does not transmit numerous packets, the CWND of the new primary path almost equals to the initial value and starts to increase by congestion control mechanism. This paper presents a Fast Handover Recover - SCTP (FHR-SCTP) mechanism that can fast recover the congestion window (CWND) after handover. FHR-SCTP improves the time of reaching the max CWND about 0.83% to 29.11% with other mechanisms after handover.